I want to scan an A4 paper, but I don't have a scanner.

My Android device has a good camera though, so I take a picture of it and I end up with a JPG file that is pretty sharp but has the following problems:

  • Cushion distortion
  • White is rather grey-yellow
  • Margins around the paper

I am looking for an app to automatically:

  • Detect and fix the distortion
  • Guess where the white is and make it really white, to make the result more beautiful and increase compressibility, without reducing readability
  • Detect and crop out the margin, so that the resulting file is the same shape as the paper. Paper border can always be guessed by seeing the shadows and differences in colour.


  • Free, ideally open source
  • Run on Android
  • Can save the result to the SD card (I should not be required to register to some cloud service)
  • Any sensible output format is fine, for instance PNG or PDF
  • 1
    A clear candidate for my Scan2PDF app list; I've never used any such, so I cannot give an answer ;) Heard good things about CamScanner, though – which also happens to be the top-rated app in this section. Check out the reviews linked to each of the apps which sound interesting to you, which should help you decide, and be welcome to answer your own question then ;) – Izzy Feb 29 '16 at 6:56
  • Look what I just found to also satisfy your "open source" wish: Open Note Scanner. Brand new, just came out 5 days ago. Added it straight to my above linked list and, well, it replaces CamScanner as the "number one" on it :) – Izzy Feb 29 '16 at 12:39

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